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Solving crystal structures from kinematical X-ray or electron diffraction patterns of single crystals requires many more diffracted beams to be recorded than there are atoms in the structure, since the phases of the structure factors can…

Materials Science · Physics 2023-02-13 Christoph T. Koch

We provide the modified TOV equations for the hydrostatic equilibrium of charged compact stars within the metric $f(R)$ gravitational background. We adopt the MIT bag model EoS for the dense matter and assume a charge distribution where the…

General Relativity and Quantum Cosmology · Physics 2022-09-23 Juan M. Z. Pretel , José D. V. Arbañil , Sergio B. Duarte , Sergio E. Jorás , Ribamar R. R. Reis

In this paper we find an analytical solution of the equilibrium ion distribution for a toroidal model of a ionic channel, using the Perfect Screening Theorem (PST). The ions are charged hard spheres, and are treated using a variational Mean…

Biological Physics · Physics 2009-11-11 A. Enriquez , L. Blum

The evaluation of the electrostatic potential is fundamental to the study of condensed phase systems. We discuss the calculation of the relevant lattice summations by Ewald-type techniques. A model charge density is introduced, that cancels…

Materials Science · Physics 2026-04-14 Chiara Ribaldone , Jacques Kontak Desmarais

Relevant uncertainties on theoretical atomic data are vital to determine the accuracy of plasma diagnostics in a number of areas including in particular the astrophysical study. We present a new calculation of the uncertainties on the…

High Energy Astrophysical Phenomena · Physics 2022-01-19 Liyi Gu , Chintan Shah , Ruitian Zhang

Electron charge density is a fundamental physical quantity, determining various properties of matter. In this study, we have proposed a deep-learning model for accurate charge density prediction. Our model naturally preserves physical…

Materials Science · Physics 2023-09-27 Taoyuze Lv , Zhicheng Zhong , Yuhang Liang , Feng Li , Jun Huang , Rongkun Zheng

Within quantum chemistry, the electron clouds that surround nuclei in atoms and molecules are sometimes treated as clouds of probability and sometimes as clouds of charge. These two roles, tracing back to Schr\"odinger and Born, are in…

Quantum Physics · Physics 2021-07-02 Charles T. Sebens

Large-scale cosmological simulations of galaxy formation currently do not resolve the densities at which molecular hydrogen forms, implying that the atomic-to-molecular transition must be modeled either on the fly or in postprocessing. We…

We present a cluster-based density-functional approach to model charge transport through molecular and atomic contacts. The electronic structure of the contacts is determined in the framework of density functional theory, and the parameters…

Mesoscale and Nanoscale Physics · Physics 2008-12-04 F. Pauly , J. K. Viljas , U. Huniar , M. Hafner , S. Wohlthat , M. Burkle , J. C. Cuevas , G. Schon

We study crystal nucleation of the Weeks-Chandler-Andersen (WCA) model, using the recently introduced Persistent Embryo Method (PEM). The method provides detailed characterization of pre-critical, critical and post-critical nuclei, as well…

Soft Condensed Matter · Physics 2018-10-26 Shang Ren , Yang Sun , Feng Zhang , Alex Travesset , Cai-Zhuang Wang , Kai-Ming Ho

We try to improve the Thomas-Fermi model for the total energy and electron density of atoms and molecules by directly modifying the Euler equation for the electron density, which we argue is less affected by nonlocal corrections. Here we…

Statistical Mechanics · Physics 2007-05-23 Jeng-Da Chai , John D. Weeks

A new method of the phase determination in X-ray crystallography is proposed. The method is based on the so-called "minimum charge" principle, recently suggested by Elser. The electron density function $\rho$ is sought in the form…

Condensed Matter · Physics 2018-09-28 P. Kalugin

The nature of pulsar is still unknown because of non-perturbative effects of the fundamental strong interaction, and different models of pulsar inner structures are then suggested, either conventional neutron stars or quark stars.…

High Energy Astrophysical Phenomena · Physics 2013-04-30 Jiguang Lu , Renxin Xu , Hua Feng

The nuclear $\alpha$ decay of heavy nuclei is investigated based on the nuclear energy density functional, which leads to the $\alpha$ potential inside the parent nucleus in terms of the proton and neutron density profiles of the daughter…

Nuclear Theory · Physics 2017-03-22 Yeunhwan Lim , Yongseok Oh

Crystal nucleation is relevant across the domains of fundamental and applied sciences. However, in many cases its mechanism remains unclear due to a lack of temporal or spatial resolution. To gain insights to the molecular details of…

Soft Condensed Matter · Physics 2024-04-05 Ziyue Zou , Eric Beyerle , Sun-Ting Tsai , Pratyush Tiwary

Simplified, classical models of water are an integral part of atomistic molecular simulations, especially in biology and chemistry where hydration effects are critical. Yet, despite several decades of effort, these models are still far from…

Chemical Physics · Physics 2015-01-13 Saeed Izadi , Ramu Anandakrishnan , Alexey V. Onufriev

Counting statistics of charge transfers in a point contact interacting with an arbitrary quantum system is studied. The theory for the charge specific density matrix is developed, allowing the evaluation of the probability of the outcome of…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 J. Rammer , A. L. Shelankov , J. Wabnig

X-ray crystallography is the predominant method for obtaining atomic-scale information about biological macromolecules. Despite the success of the technique, obtaining well diffracting crystals still critically limits going from protein to…

The model independent procedure of extracting charge density distributions from elastic electron scattering data is investigated. The charge density distributions are expanded on an orthonormal basis and the parameters of the expansions are…

Nuclear Theory · Physics 2019-08-17 R. Anni , G. Co' , P. Pellegrino

A method to derive the charge current density and its quantum mechanical correlation from the scattering matrix is discussed for quantum scattering systems described by a time-dependent Hamiltonian operator. The current density and charge…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Tooru Taniguchi